Coated dustless, granular insecticide for flies, their larvae, and other insects



COATED DUSTLESS, GRANULAR INSECTICIDE llgi lcl rlllls, THEIR LARVAE, ANDOTHER Julian H. Jackson and Herman S. Mayeux, Jacksonville,

and William J. Head, Lake Jem, Fla., assignors to Wilson & ToomerFertilizer Co., Jacksonville, Fla., a corporation of Florida No Drawing.Application September 6, 1956 Serial No. 608,219

20 Claims. (Cl. 167-42) This invention relates to an insecticidalcomposition in a free-flowing, granular form, which composition isparticularly effective against flies, especially house flies (Muscadomestica L.), in the adult and larval stages, soldier fly larvae(Hermetia illucens L.), and also adults and larvae of certain other flyspecies. It is also effective in killing other insects, such ascockroaches and ants. It is readily pourable from boxes, bags or othercontainers of similar structure; it can be shaken from containers withperforated tops. Another advantage is that it can be readily applied byhand or mechanically. Nevertheless, it exhibits relative freedom fromdust formation either in pouring or shaking it from containers or onscattering it by hand upon surfaces. It is both relatively free ofloose, unattached pulverulent particles and substantially free fromclumping. However, when compounded with care in the selection of thetoxicant chemicals the insecticidal composition exhibits a relativelow-level of toxicity to human beings and other warm blooded animals.Because of various of the above properties, it is particularly adaptablefor marketing in packages, in ready-foruse form.

Insecticides for fly control are applied in those areas where flies tendto congregate and/or breed, such as dairy barns and other livestockbarns and pens, poultry houses, manure piles, garbage dumps, thevicinity of garbage cans, and also on the grounds contiguous tobuildings or the porches of residences and in similar areas.

The usual or customary types of insecticides for housefly control areintended for sprays and baits, and are usually liquid in nature. Adisadvantage of the former is that the application of sprays to infestedareas is laborious and requires the use of some type of mechanicalsprayer equipment. Many fly bait preparations come to the user in liquidor dry form to be mixed with water or a similar liquid by the user priorto application. They are applied in such modes as: in separatecontainers, on absorptive material such as burlap, or on the floor,walls or ground often by means of a sprayer or sprinkler can.Furthermore, such baits are generally designed for use against the flyin adult stage, rather than against both the larval and adult stages.

The granular insecticide of'the present invention is not to be confusedwith a dry pulverulent powder which is the type of pest controlcomposition which is conventionally applied as a dust or spray. Incontrast, our granular insecticide is relatively free of unattachedpulverulent particles. The physical nature of the product of the presentinvention permits it to be easily applied by hand and the particlescomposing it are much easier to direct to the focal area, even thoughthere are air cur rents, than a powdered product would be under the sameatmospheric conditions; then too, more of the product of the presentinvention comes to rest upon the selected focal area and not upon othersurfaces where an application of the insecticide is undesired, since itis not carried away by the wind.

The insecticidal'cornposition which we have invented acts instantly orrapidly, i. e., within a few minutes to kill either the adult house flyonly or the house fly' in both the adult and larval stages, and itslethal effectiveness lasts for several days in areas sheltered fromrains. A good portion of it stays on the surface after application tothe focal area, whereby flies can get at the insecticide. Ourinsecticidal composition permits a much lower concentration of thetoxicant contained therein to be used to do a more effective job inkilling house flies in the adult and larval stages than is possible whenusing the same toxicant and attractant on granular fullers earth orother absorbents under identical conditions.

The present invention is a continuation-in-part of patent applicationsof the same inventors identified as Serial Numbers 408,034, filedFebruary 3, 1954, and 455,072, filed September 9, 19-54, but nowabandoned. The prior published art admitted and discussed in theaforesaid patent applications was an article by l as. B. Gahan and W. C.McDufie appearing in Agriculture and Food Chemistry, vol. 28, page 425,issue of April 14, 1954; the Baker Patent #1,450,128, issued May 27,1923; other U. S. patents, namely #1,733,958, #2,268,l08, and#2,547,822. In like manner, each is herewith again acknowledged.

The granular insecticide of the present invention is characterized byinorganic, water-insoluble, non-porous granules, preferably oyster shellor other calcareous shell of particle size range from 3 to screen mesh,inclusive, coated with an oil and an oil-dispersible, organic toxicantfor the insect and an organic attractantfor the insect. A concentratedaqueous solution of sorbitol can also be used as the coating liquid, towhich there has been added preferably thickening agents. The insecticideis free-flowing, but is not dusty when poured or when scattered by handonto a solid surface. The amount of oil or solution of sorbitol shouldbe sufficient to thoroughly coat the granules, yet without excessiveWetting to the condition or point of excessive stickiness or lumping ofparticles. The coated granular insecticide is substantially free ofloose, unattached pulverulent particles. The inorganic, water-insoluble,non-porous granular material should constitute at least substantiallytwo-thirds by weight of the solid carrier; it is preferred for this typematerial to comprise all of the solid carrier; and a solid granularcarrier formed wholly of oyster shell is best of all. The non-porous,inorganic, water-insoluble granules further constitute the majorcomponent by weight in the finished granular insecticide, and as is .tobe perceived from the examples herein its weight exceeds that of theother components in the finished insecticide. The pulverized particleswhich are present, whether powdered sugar or other organic attractantfor the insect, or incidental amounts of finely divided particlespresent in the solid carrier material or from whatever source are causedto stick or be physically strongly bound to the granules due to thecoating media. This is true as to dispersant and other optionalconstituents in formulating the granular insecticide.

There may be, and preferably is, included in the granular insecticidalcomposition of the instant invention, a dispersant for the organictoxicant when the latter is not appreciably water-soluble, in order toscatter it into and through the moisture that comes in contact with thegranules of solid insecticidal material.

A dye of any desirable color, such as red, may be added and incorporatedin the granular insecticidal composition. Its use is quite optional.

Another alternative material which may be incorporated is a stabilizer.The role of such a component is to reduce the speed of breakdown of theorganic toxicant. It has been found that weak acids, either inorganic ororganic, or other acidic reacting compounds such as Patented Jan. 28

3 salts will reduce the speed of breakdown of Malathionl wherealkalinity is present in the surface materials to which the granularinsecticidal material is applied. Hence, boric acid and other 'weakacids such as citric or tartaric, or acidic reacting components can beincorporated, provided their presence does in no way hinder the generalperformance of the finished insecticidal composition.

The preferred inorganic, non-porous, water-insoluble granular materialwe use is oyster shell, which is in a clean (free from debris), dry,ground condition, and particularly ground oyster shellhaving twoparticular size ranges within the overall range stated herein after.

Other calcareous shell can be used satisfactorily. By shell is meant theexo-skeletons of zoological animals belonging to the phylum Molusca,class Lamellibranchia or Pelecypoda (also known as bivalvia, whichincludes such animals as oysters, clams, mussels, scallops, etc.). Thisclass is distinguished by having the body bilaterally symmetrical,compressed and more or less completely enclosed within the mantle, whichsecretes a bivalved shell whose right and left parts are connected by ahinge, over the animals back. There is no distinct head, and there areusually two lamelliform gills on each side of the body. The term shellin our invention is intended to include both processed and unprocessedform, the former meaning broken up and sized, with or without prewashingor other steps.

Other specific non-porous, water-insoluble inorganic substances whichmay be used in granular form as carriers are sand and quartz (forms ofsilica) and granite. However, calcareous shell is a better carrier thanany of these substances, and superior to all of the aforesaid non-poroussubstances is oyster shell.

We have successfully used for fly control granules of these aforesaidcarrier substances whose particle sizes range between one-quarter inch,i. e., 3 screen mesh, and 100 screen mesh, Tyler Screen Series (TylerStandard Screen Scale Sieves of W. S. Tyler Company of Cleveland, Ohio).If the particle size is larger than screen mesh 3, then at reasonablequantitative rates of application of shell, i. e., shell weight/surfacearea in square feet treated, the number of solid particles deposited persquare foot is so low as to reduce the lethal effectiveness of theapplication. In the present invention, the term granular is understoodto mean the carrier material of particle sizes which will pass throughscreens ranging from one-fourth inch, i. e., substantially mesh size 3as the largest size, to 100 screen mesh as the smallest size, inclusive(Tyler Standard Screen Scale Series of the W. S. Tyler Company). It isrecognized that as a fact there usually is a fraction of a percent to afew percent of particles, based upon the total weight of shell, whoseparticles are smaller in size than screen mesh 100.

For adult fly control we have found that solid particles of range to 20screen mesh are most desirable. For the larvae or maggots we have foundthat solid particles of range 20 to 40 screen mesh are most desirable.For the combined control of both larvae and adult flies, We prefer amixture of particles having eighty percent (80%) of particles rangingfrom 10 to 20 screen mesh and twenty percent (20%) of solid particlesranging from 20 to 40 screen mesh. However, for the combined control ofboth adult flies and larvae, a mixture of particles having eightypercent (80%) of the particles ranging from 10 to 20 mesh and twentypercent (20%) of the solid particles ranging from 60 to 100 screen meshmay be used. Furthermore, a mixture containing eighty percent (80%) ofsolid particles ranging from 3 to 20 screen mesh and twenty percent from20 to 100 screen mesh may be used. In manufacturing it is oftendesirable to obtain a screening cut of particles ranging approximately85% from 10 to 20 screen mesh, 10% from 20 to 30 screen mesh andapproximately 5% of smaller screen mesh sizes. The fine particles addappreciably .to the number of particles deposited per square inch ofsurface to which the insecticidal composition is applied, and result inbetter distribution of the toxicant; in this way more of the larvae comein contact with the toxicant. The disadvantage of particles finer thanscreen mesh and even particles smaller than 40 mesh is that the productmade therefrom is likely to be dusty, and dustiness is not desirable.There usually is a very minor, incidental amount of powder in thegranular, inorganic solid material of size range one-quarter inch-100screen mesh.

Oyster shell or other calcareous shell can be admixed with sand, quartz,or granite or other inorganic, nonporous, water-insoluble granules. Itis preferred for the carrier to be as nearly wholly shell as possible,there being some extraneous materials such as sand or other solid inshell or associated with it in a natural condition or in the processedstate. Likewise a mixture or combination of any two or more of othersaid non-porous granules may be used if oyster shell or other calcareousshell is not employed as the carrier. It will be understood that it isyet within the spirit of this invention for such inorganic, non-porousgranular material to be replaced in part by organic, non-porous granularsubstances, of which broken or unbroken rice grains would be an example,and wherein this type inorganic granular mtaerial is the dominantportion of the entire carrier, being not less than substantiallytwo-thirds thereof in weight. It will further be understood that theaddition or substitution of a few percent by weight, based upon thetotal carrier, of porous granular substances such as, for example,fullers earth or bentonite or silica gel or tobacco stems, may be usedbut the addition of porous type granular substances is not desirablebecause of their absorbency. Very minor amounts of powder from any ofthe aforesaid sources may be present, usually incidental in the grindingor screening to prepare the granules.

Shell has certain advantages in the type of insecticidal compositionshaving a granular base. It is easily converted into the range ofparticle size desired. It has a density great enough (substantially 2.54sp. gr. for oyster shell) to resist interference by the wind in the actof being distributed by hand or mechanically, and is sufficiently heavyto remain on the surface of application and not be readily blown awaylater. It is not as dense as sand (substantially 2.54 sp. gr. for oystershell vs. 2.64 for sand), nor as light as expanded mica, cut tobaccostems, citrus pulp meal or sawdust. The granules of shell arepredominantly flat, which is another reason they are not easily blown bythe wind after they come to rest on a surface. As a result of theflattened shape, there is more surface area exposed to the insect thanexists in the same weight of granite, sand or quartz of the same meshsize range. The bulk density of shell is much greater, the comparisonbeing on the same screen mesh size, than for granite, sand or quartz(for a sand screening 20-30 mesh found 1.47 as against 0.96 for oystershell of same range screen mesh). Shell possesses low porosity;therefore the toxicant and other ingredients are adsorbed on the surface.but are not absorbed in the solid. The light color of shell 'is anadvantage to the user because he can perceive the coverage ordistribution upon a treated surface. Shell, unlike fullers earth,bentonite, and expanded mica, is not slippery underfoot when wet bywater but increases traction. This is important on smooth, hard surfacessuch as concrete floors.

As explained previously, there are various kinds of processed shell,including oyster, clam, mussel and scallops. There is also a mixture ofshell sold as reef shells. The term refers to shell coming from an areathat is a reef topographically and is a natural mixture of several kindsof shell in widely varying ratios, such as oyster, clam, scallop, conch,etc. We prefer to use oyster shells which arein a clean (free'of debris),;.dry,

ground condition, and especially shell'having two-parhole size ranges. I

Various non-volatile oils have been employed as coating liquids andfound to be suitable. We prefer nondrying oils of the mineral type orglyceride type, or semidrying oils nextin this coating liquid selection.Any non-drying or semi-drying vegetable, animal or marine oil or mineraloil may be used, provided the oil is attractive to or at least notappreciably repellant to the insects, and further provided the oil willserve its major purposes: to carry the toxicant in true or colloidalsolution or dispersion, to cause the various ingredients to stick to thegranules of the solid carrier material. Examples of suitable vegetableoils, are peanut, cottonseed and olive oils. Bland mineral oils, whichare refined mineral oils, are suitable. The bland mineral oils are usedrather than those with an undesirable odor. Marine oils, unless veryhighly refined, are usually offensive to human beings. Whereas thenon-volatile oil selected may itself possess certain incidentalattractive properties for flies or other insects, it is not classed asan attractant for insects, but the coating liquid. When the insecticidalcomposition is also to be employed against larvae as well as adultflies, the oil which is selected must be capable of being dispersedalong with the toxicant by the dispersant.

- When a non-volatile oil is employed as the coating liquid the insecttoxicant should be dispersible or miscible in the oil. By this is meanta true solution, a colloidal solution or dispersion. There are variousorganic type toxicants which are oil-soluble or dispersible in oil andhave been found to be lethal toward flies and/or their larvae. Thetoxicant employed should not impart an odor to the finished insecticidalcomposition which is offensive to humans, or more than very mildlyoffensivea factor in commercial acceptance of the insecticide. We preferto use 0,0-dimethyl dithiophosphate of diethyl mercaptosuccinate whichis also known under the coined name Malathion or Malathon. Theconcentration of this substance which we have found works best is onepercent (1%) by weight of the total composition, i. e. the granularinsecticide, when the particle size range is predominately to 20 screenmesh. For particle sizes ranging predominately from 20 to 40 mesh, it isdesirable to increase the Malathion to two percent (2%) concentration oreven higher, because of the increased surface to be coated. Malathion isa heavy liquid. It is preferred to select the technical grade of atleast 95% purity because we have observed that such purified materialdoes not impart an odor olfensive to human beings to the granular bait,whereas technical Malathion" of less than 95% purity sometimes emits afaint but offensive odor to the finished granular bait.

Another very lethal organic toxicant which is effective against adultflies and even superior to Malathion against fly larvae is Diazinon. Itis used in concentrations of the order that Malathion is employed.Diazinon is the trademark designation employed by Geigy ChemicalCorporation, and is understood to be 0,0-diethyl-O- (2isopropyl-4-methyl-pyrimidyl (6)) thiophosphate.

0,0 dimethyl 1 hydroxy 2,2,2 trichloroethylphosphonate. It is also knownas 0,0-dimethyl-2,2,2 trichloro-l-hydroxyethyl phosphonate; the productis sold under the trademark Dipterex (a product of Chemagro Corporationof New York city); it is a toxicant of the water-miscible type. It islethal both to adult house flies and fly larvae.

.Lindane is another oil-dispersible insect toxicant, ef fective againstadult house flies. Chemically it is essentially the pure gamma isomer ofbenzene hexachloride. The technical grade with gamma isomer content ofover 99% is preferred.

Dilan which is composed of a mixture of 2-nitro- 1,1-bis(p-chlorophenyl) propane and .2-nitro 1,1 -bis (pr-chlorophenyl)-butane,and which is"'oil-soluble*can 'be used as-the .toxicant, since it islethaltowardflies.

Neither Lindane nor Dilan is as effective against house flies as thefirst three mentioned.

Other toxicants which are oil-soluble or oil-dispersible and possess inlow concentrations lethal action .toward house flies and other fliesand/or other insects and their larvae, yet which possess low toxicitytoward warm blooded animals may be used. The order of toxicity towardflies and other insects will vary and the specificity as to the variouskinds of insects; this will affect the choice of toxicant. Theconcentration of the toxicant will vary with its lethal effect inrespect to the insect host. In general, the lower range is 0.1% and thehighest range 10% by weight of the granular insecticide.

The quantity of oil or concentrated aqueous solution of sorbitol to beused should be sufiicient to thoroughly coat the granules of the carrierand the other dry components in the granular insecticide yet withoutexcessive wetting to. the condition or point of excessive stickiness orlumping of the particles. The quantity of oil in reference to a givenweight of granular carrier will depend upon the nature thereof in sizesof particles and to some extent upon the kind of material being coated.In reference to all the dry material, and to state this in another way,the amount of oil or concentrated aqueous solution of sorbitol dependsupon the phenomena of adsorption or absorption, the factors in which arethe amount of surface area to be coated and the degree of porosity ofthe particles. From the subsequently presented examples, it will be seenin Examples 1 and 2 that 3.l% has been found to be ample for oil forgranular oyster shell of coarse and fine sizes, and 2.5% when using onlythe coarse size. If there is too little oil or sorbitol the finishedproduct will lack maximum attractiveness to the insects and maytend'toward dustiness. The undesirable aspect of dustiness has beenpreviously mentioned.

If the organic, insect toxicant is not soluble in water appreciably oris present as a dispersion in oil, it is advantageous to employ adispersant for it; this is more particularly true when the granularinsecticide is to be used, to kill the fly larvae, or any other insectlarvae.

The role of the dispersant is to scatter the toXicant-oil solution intoand throughout the moisture that comes in contact with the granules ofsolid insecticidal material; this can be viewed as an emulsifying actionwhen the dispersant is the emulsifying or penetrating agent. One whichWe have used in many formulations is a high purity sodium naphthalenesulfonate known as Petronate (marketed by L. Sonnenborn & Sons, Inc., ofChicago, Illinois). This is representative. of the organic sulfonic acidtype. And the sodium acid sulfate of a higher alcohol type compoundwould function in an analogous way, such as sodium lauryl sulfate, butare more costly.

. Another dispersant, but entirely different chemically, is Maypon, amaterial condensation proteinaceous material obtained from chromeleather oils (product of Maywood Chemical Works of Maywood, New Jersey).However, other compounds or mixtures that are miscible and compatiblewith the other liquid ingredients and can disperse the toxicant-oil inwater, yet are not objectionable to the adult insects, can be employed.1

Previous mention has been made of the quite optional use of a dye. Thedye which we prefer to use is known as Du Pont Woodstain Scarlet. A dyeserves several purposes, to wit: acts as a color indicator to themanufacturer in determining the thoroughness of distribution of theliquid or semi-solid coating material upon the solid particles, confersattractiveness in appearance to the user, facilitates distinguishment ofthe insecticidal composition from the surfaces upon which it lies andrenders the particles more conspicuous to the human eye.

It will be understood that a blend of two or more oils can be employedinstead of one oil, and that in the same way a mixture of each of theother essential components can be used and/or dispersant and/orstabilizer and/or dye; the latter three are desirable under certainconditions, more particularly the dispersant.

The attractant for the flies or other insects which we preferto use issugar (sucrose), and in the powdered form. Other sugars can be used,including glucose and fructose. Tupelo honey can be used and does notcrystallize. The attractant is suspended in the non-drying orsemi-drying oil or concentrated aqueous solution of sorbitol. We haveobserved that the combination of sugar (sucrose) and glyceride type oilfrom vegetable sources is more attractive to flies and certain otherinsects than either used separately. Molasses is not as satisfactoryowing to a tendency to spoil under warm weather conditions. Powderedmilk can be used. Two or more insect attractants may be mixed togetherand used. Various synthetic organic chemicalshave been used informulations which increase attractiveness to the insects. Suchattractants are used with sucrose or other sugars; they have odor offlowers, stables or other odors attractive to flies. Some of these areFritzsche Brothers, Inc. (Port Authority Bldg, 76 9th Ave., N. Y., N.Y.) Fly Attractants No. 25091 and 25092, and Polaks Frutal Works, Inc.,Middletown, N. Y., Fly Attractants Nos. 1, 2 and 3. The percentage ofattractant in the finished product may be varied, as well as the choicethereof, as appears necessary to accomplish the desired result, namelythe death of flies and/ or other insects.

The usual commercial way in which this granular insecticide is made isto mix all the solid components thereof in one mixer. The liquid orsemi-solid components are mixed separately and this mixture in turn isadded to the mixture of solids, the mass being thoroughly stirred. WhenArlex is used, a coating liquid containing a very high percentage ofsorbitol, subsequently mentioned, we find it is best to mix all the drysolid ingredients except sugar; the liquid mixture is added, and lastthe sugar in dry form is added, and the mixing operation continued.

By another mode in the manufacture of the product of the presentinvention, the toxicant, the oil, and the attractant are intimatelymixed together with the dispersant, the stabilizer (acid) and dye. ifany or all of the latter three ingredients are also to be incorporated.The coating operation which follows this step is best accomplished bymixing, wherein the solid granules are stirred or tumbled while theliquid mixture is being poured upon the granular mass and for a fewminutes thereafter. These are not the only ways that the production ofthe coated solid granulescan be achieved. The various modes will dependof course upon choice and/or the components which form the coatedgranular insecticides, which in other embodiments may not include anoil. Mixing of small amounts may be done by hand by using a suitablepaddle and a container such as a bucket. In larger quantity operations,such as would be used commerciallyyarious types of mechanical mixersthat are capable of physically mixing'the liquid mixture with the solidgranules, such as a ribbon-type mixer or a paddle-type mixer of whichthe pony mixer is one, can be utilized.

As has become apparent from the above disclosure, neither toxicant noroil nor dispersant nor any of the granular solid materials should reducethe attractiveness of the final product toward flies and other intendedhosts perceptibly. Hence, care should be exhibited in the selection ofthese respective components in determining the formulation.

A commercially available non-crystallizing aqueous polyhydric alcoholsolution consisting of sorbitol and anhydrides and other polyhydricderivatives of sorbitol which prevent crystallization of the solutionmay be used. The product goes by the trademark Arlex and is sold byAtlas Powder Company of Wilmington, Delaware. It has but a faint odor,and its viscosity is approximately 1700 cp. 25 C. The analysis of itsproducer states that the polyhydric alcohol content is at least 83.0%.Sorbitol is a hexa-hydric, aliphatic alcohol. Its aqueous solutionisclassified as a humectant. Instead of Arlex," other aqueous solutionsof sorbitol, one of such being a 76% aqueous solution of sorbitol andits anhydridcs, of which polyhydric alcohol content is sorbitol (sold bythis same company) may be used. These aqueous solutions of sorbitol bothact as a coating liquid like the oils and to prevent loss of water ordrying out, and clodding or clustering of the finished granularinsecticide. From the examples hereinafter it will be perceived thatArlex" which has a high viscosity, much higher than that of the 76%aqueous solution of sorbitol (approximately 300 cp. 25 C.), and a higherpolyhydric alcohol content, is more frequently used. The lowest sorbitolcontent in such coating liquid is to be formed in Example 15 wherein thesorbitol content is one-half that of the water, namely /a: /s. Sorbitol,chemically, is not a hexose, not being aldehyde nor ketone alcohols.

Gum arabic, pectin and gelatin may each be used as a constituent in thecoating material. Powdered gum arabic absorbs sorbitol during the firstfew days and swells somewhat, i. e., after being applied to the granularcarrier. Powdered gelatin and pectin do not absorb sorbitol veryappreciably, it has been our observation. These three aforesaidsubstances may also be employed when an oil is chosen as the coatingliquid. Example 7 hereinafter sets out a satisfactory method of makingthe granular insecticide when powdered gum arabic is employed. It issatisfactory when powdered pectin or gelatin is used instead of the gumarabic. When an oil is chosen instead of sorbitol as the coating mediuma variation of that method should be utilized. By this, the varioussolid components are mixed, and in a separate vessel all the liquidcomponents are mixed; and thereafter the mixture of liquids is added toand thoroughly incorporated into the mixture of solids.

Chemically, gum arabic and pectin are not similar to gelatin. Gumarabic, which is an exudate from vegetable plants, is considered toconsist of the potassium and calcium salts of arabic acid. Pectinsubstances, which occur in fruit juices, are closely allied to vegetablegums; the basic constituent is considered to be the calcium or magnesiumsalt of pectic acid. Gelatin is classified as a protein. They eachhoweverconfer body to the coating liquid by being suspended in thecoating liquid or colloidally dissolved therein; and they help bond theorganic attractant and toxicant to the solid carrier.

Hi Sil may be used as an agent to confer a body to the coating. Hi Silis the trademark designation for hydrated silica in extremely finelydivided form, sold by Columbia-Southern Chemical Corp. of Pittsburgh, adivision of Pittsburgh Plate Glass Company of Pittsburgh, Penna. theparticle size range thereof is less than 1 micron. It adsorbs on itssurface the liquid components and because of the extreme subdivision isable to hold a great amount of liquid on its surface.

The detailed description has been as to oils as thecoating liquid andoil-dispersible or oil-soluble toxicants and also as to concentratedaqueous solutions of sorbitol as the coating liquid. It will beunderstood that the general principles and the detailed mode ofmanufacture can be adopted to water-soluble toxicants. It should like tobe stated that if the attractant or toxicant has a tendency tocrystallize, the finished product where there is a high percentage ofeither component has a tendency to cake or harden, particularly if letstand on the shelf, etc. If this happens, the hard insecticide productcan be broken up, whereupon it can be poured or distributed by handwithout further difficulty. It is sometimes helpful, where the containerof the granular insecticide has been let stand many weeks, to give it athump to correct any superficial sticking ofcoated granules.

Certain advantages of the present inventionover sprays position isapplied, may become toxic toflies.

and baits for insects, more particularly for house flies and other kindsof flies have been presented, supra. But it has other significantadvantages. =Our insecticidal composition is formulated so as to beattractive to .flies but toxic tothem by contact and/ or ingestion.Furthermore, it may be so constructed that the active toxicant is ableto become separated from the solid inorganic particles which form themajor component thereof after application to a surface and pass intowhatever moisture is in contact with the solid particles; the result isthat the surrounding surface itself, upon which the solid granularinsecticidal corn- And furthermore, what is also significant, the activetoxicant, so separated from the granules, kills by contact or ingestionthelarvae of house flies and certain related species that may be withinor beneath the surface to which the in secticidal composition has beenapplied.

From the examples appended below, it will be seen that Malathion, a verylethal fly toxicant, can be employed with Arlex, which is a veryconcentrated aqueous solution of sorbitol as well as with non-volatileoils.

The invention is illustrated but not limited by the following examples:

Example 1 This formula is best suited for use against adult insects onlyand is not as effective against larvae as those set out in the next fourexamples, because this formula does not contain a dispersant.

Using coarse oyster shell:

95% technical Malathion 1.7 oz. Cottonseed oil 4.0 oz. Powdered sugar(sucrose) 1 lb. Coarse oyster shell (sizes to screen mesh) 8 lbs. 9.3oz.

- Total 9 lbs. 15.0 oz.

In this example peanut oil may be substituted in full or in part for thecottonseed oil.

Exaniple 2 This basic formula is preferred for the combined control ofadult flies and fly larvae.

Petronate 1.7 oz.

Powdered sugar (sucrose) llb.

95 technical Malathion 1.7 oz.

Peanut. oil 5.0 oz.

Coarse oyster shell (size 10 to 20 screen 6 lbs. 12.0 oz.

mesh) Fine oyster shell (size 60 to 100 screen -11b. 11.6 oz.

mesh) Total 10 lbs.

In this formula, cottonseed oil may be substituted in whole or in partfor peanut oil in the same way yet conversely, as explained in theprevious example. Petronate is a liquid.

Example 3 This formula is identical with that in Example 2 except that ared dye is employed; the amount of fine oyster shell is merely reducedslightly in' retaining the over-all weight at 10 lbs.

Petronate 1.7 oz. 95% technical Malathion 1.7 oz. Peanut or cottonseedoil 5.0 oz. Du Pont Woodstain Scarlet dye 0.2 oz. Powdered sugar(sucrose) 11b.

Coarse oyster shell (size 10 to 20 screen 6 lbs. 12.0 oz.

mesh) Fine oyster shell (size '60 to 100 screen 1 lb. 11.4 oz.

mesh) 1 10 Example 4 A formula in which boric acid employed tostabilizethe Malathion in the granular'insecticide appears in next formula. H

Technical, powdered boric acid Pe'tronate 1.7 oz.

95% Malathion technical 1.7 oz.

Peanut or cottonseed oil 5.0 oz.

Powdered sugar (sucrose) -1 lb.

Coarse oyster shell (size 10 to 20 screen 8 lbs. 5.9 oz.

mesh) Total 9.1bs. 15.0 oz.

In preparing this composition having prolonged'lethal effect towardinsects, the boric acid is mixed with the shell and sugar before addingthe-mixture of liquid components to the granules of oyster shell. Butthe boric acid could be mixed with the liquid mixture before adding thelatter to the shell and sugar.

pl 5 Percent Water-wettable powder containing 25% Malathion- 4.0Cottonseed oil 5.0 Powdered sugar (sucrose) 10.0 Oyster shell of screenmesh 10-20 81.0

Total 100.0

Example 6 I 95% technical Malathio n Q .2.0 Arlex v 4 2.0 Powdered sugar(sucrose) 5.0 Oyster shell of screen mesh 10-40 s 91.0

Total 100.0

v Example 7-v L 1 95% technical Malatbinn 0 Powdered gum arabic "1.0Powdered sugar (sucrose) 10.0 Arlex 3.0 Oyster shell (10-30 screen mesh).0

Total Q 100.0

In the preparation of the granular insecticide by this formula thepowdered gum arabic is mixed with the shell, and ina separate vessel theliquids, namely Arlex and Malathion are mixed. The liquidmixture isadded to the dry solids mix, and stirred well, after which the powderedsugar is added slowly and mixedthere'ini- 'The gum arabic absorbs theArlex during the first" few days and swells somewhat.

Example 8 g Percent technical Malathion L' iArlex! I Powdered sugar(sucrose) coat the shell.

Example 10 9.5% technical Malathion -2 1.0 Arlex 2.0 Powdered sugar(sucrose) 10.0 Granite 10-20 screen mesh) 87.0

Total 100.0

Example 11 95% technical Malathion; 1.0 Arlex 3.0 Powdered sugar(sucrose) 10.0 Granite (l20 screen mesh) 57.0 Broken rice grains 29.0

Total 100.0

Example 12 95% technical Malathion 1.00 Arlex 1.75 Powdered sugar(sucrose) 10.00 Sand (2.0-30 screen mesh) 87.25

Total 100.00

Example 13 95% technical Malathion 1.00 Powdered gurn arabic 1.00 Arlex1.50 Powdered sugar (sucrose) 10.00 Sand (20-30 screen mesh) 86.50

Total 100.00

Example 14 95% technical Malathion 1.00

Arlex 2.25

Powdered sugar (sucrose) 10.00 Sand (20-30 screen mesh) 57.75 Brokenrice grains (-30screen mesh) 29.00

Total 100.00

Example 15 In this example a. water-soluble insect toxicant dissolved inwater containing also sorbitol (a humectant) and an organic attractantfor the insects is applied to The granular insecticide is lethal toadult house flies and fly larvae.

- Percent 0,0-dimethyll-hydroxy-2,2,2 trichloroethylphosphonate 1.0Sorbitol 2.0 Water 4.0 Granular sugar 2 10.0 Oyster shell of screen mesh10 size 66.5 Oyster shell of screen mesh 60-100 size 16.5

Total 100.0

Sorbitol prevents drying out and clodding or clustering of the finishedinsecticide.

This finished composition, because of the high percentage of sugar,tends to harden upon aging. If and when this occurs the hardenedproductcan be crushed, and thereafter this condition will not reappear.By re- .dueing the percentage of sugar and increasing the amount.of-aorbitol, this tendency can be counteracted;

12 Example 16 Percent 95% technical Malathion 1.35

Petronate 1.00

Arlex 2.00 Powdered sugar (sucrose) 5.00 Oyster shell (10-30 screenmesh) 90.65

' Total 100.00

Example 17 95% technical Malathion 1.5 Arlex 0.5 Powdered sugar(sucrose) 5.0 Powdered gelatin 2.0 Sand (10-30 screen mesh) 91.0

Total 100.0

Example 18 95% technical Malathion 1.00 Du Pont Woodstain Scarlet dye0.01 Powdered gelatin 2.00 Mineral oil, bland 2.50 Powdered sugar(sucrose) 5.00 Oyster shell (1030 screen mesh) 89.49

Total 100.00

Example 19 95% technical Malathion 1.00 Du Pont Woodstain Scarlet dye0.01 Powdered gelatin 2.00 Arlex 2.50 Powdered sugar (sucrose) 5.00Oyster shell (.10-30 screen mesh) 89.49

Total 100.00

Example 20 95% technical Malathion 1.00 Du Pont Woodstain Scarlet dye0.01 Powdered gelatin 2.00 Arlex 0.75 Powdered sugar (sucrose) 5.00Granite (10-20 screen mesh) 91.24

Total 100.00

Example 21 Diazinon solution (in xylene) 1.45 Petronate 1.00 Arlex 2.00Powdered sugar (sucrose) 5.00 Oyster shell (IO-30 screen mesh) 90.55

Total 100.00

Example 22 80% Diazinon" solution (in Xylene) 1.25 Petronate 1.00Mineral oil, bland 2.00 Powdered sugar (sucrose) 10.00 Oyster shell(10-30 screen mesh) 85.75

Total 100.00

Example 23 technical Malathion 1.0 Powdered pectin 2.0 Arlex 2.5Powdered sugar (sucrose) 5.0 Oyster shell (10-30 screen mesh) 89.5 TotalI Example 24 95% technical Malathion 1.0 Powdered pectin 2.0 Arlex 1.0Powdered sugar (sucrose) 5.0 Granite (10-20 screen mesh) 91.0

Total 100.0

Example 25 95% technical Malathion 1.0 Powdered pectin 2.0 Arlex 0.75Powdered sugar (sucrose) 5.0 Sand (20-30 screen mesh) 91.25

Total 100.00

Example 26 95 technical Malathion 1.0 Arlex 1.0 Tupelo honey 5.0 Oystershell (10-20 screen mesh) 83.0 Oyster shell (60-100 screen mesh) 10.0

Total 100.0

Example 27 95% technical Malathion 1.0 Arlex 1.0 Tupelo honey 5.0 I-liSil 2.5 Sand (20-30 screen mesh) 90.5

Total 100.0

It has been found that as little as one-fourth pound of the finalgranular insecticide per 100 square feet of surface is usuallysuflicient to control adult house flies. We have found that it is notnecessary to treat all of the infested area because the product has thecharacteristic of attracting flies in the immediate vicinity to feedupon the bait. Adult flies usually become affected by the poison withintwo or three minutes after feeding upon this insecticide. In coldweather this time may be as long as to minutes, depending upon thetemperature. Death of the flies occurs within a few minutes after thefirst sign of toxic effects, in most instances. Adult flies have beenobserved dying as the result of feeding upon particles ofthisinsecticidal compound that were applied on a dry surface seven daysearlier. This observation has been repeatedly checked. Ability to causedeath to adult flies after seven days shows the prolonged lethalproperties of the coated granular insecticide of our invention.

Against the larval stage of thehouse fly and other fly species, it isnecessary to use as much as one or two pounds of the granularinsecticide per 100 square feet of surface to the manure or otherincubating grounds in which the larvae are feeding. The granules oftenpenetrate into the matrix, particularly if the matrix is itself granularin nature, and especially when larvae are numerous in the matrix. Themovement of the larvae aids greatly in mixing the granules into it. Thetoxicant penetrates into the matrix, the rate depending upon the amountof surface moisture present in the matrix. House fly larvae that arevery near the surface usually begin to die within 30 minutes. Larvae dieover a period of two to seven days, depending upon the toxicant used,where present in a depth of two or three inches in the matrix, dependingupon the penetration of the toxicant and movements of affectedindividual larvae. i

It has been found that the best way in which toapply the insecticidalcompound of the present invention is to scatter the granules by handover the area to be treated.

14 It may be expedient to protect'the hand of the individual against thetoxicant by some form of glove where the human skin' is brought intocontact for a prolonged period of time; and, as a further precaution,the hands should be washed after use to avoid any possible toxic eifectof the Malathion or other toxicant therein upon the user. It is possiblealso to distribute it from a shaker top type of container, whereby anycontact with the skin would be avoided.

While there are above disclosed but a limited number of embodiments ofthe granular insecticidal product of the invention herein presented, itis possible to produce still other embodiments without departing fromthe inventive concept herein disclosed. It is desired, therefore, thatonly such limitations be imposed on the appended claims as are statedherein.

The term non-porous is used in the claims as also embracing the physicalcharacteristic of not being capable of occluding the coating liquid orsemi-solid inside the granules. The term relatively non-drying toqualify oil is understood to include either an oil that is nondrying orsemi-drying. The term in the claim oil solution or solution in an oil isto be construed to embrace a dispersion in addition to a true orcolloidal solution. And the designation of particle size by screen meshrefers to the Tyler Standard Scale Sieves.

We claim:

1. An insecticidal composition in granular form, characterized byinorganic, non-porous, water-insoluble granules with particle size rangefrom 3 to screen mesh, inclusive, as a carrier coated with an oilsolution of an organic toxicant for the insect, and an organicattractant for the insect, which inorganic granules constituteapproximately the entire solid carrier in the granular insecticide, andwhich oil is substantially non-volatile at atmospheric temperatures andrelatively non-drying, the said granular insecticide being relativelyfree of loose, unattached pulverulent particles, substantially free fromclumping and readily pourable, and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

2. An insecticidal composition in granular form, characterized byinorganic, non-porous, water-insoluble granules with particle size rangefrom 3 to 100 screen mesh, inclusive, as a carrier coated with an oilsolution of an organic toxicant for the insect, and an organicattractant for the insect and a dispersant for the toxicant-oil solutionas to moisture that comes in contact with the granules, which inorganicgranules constitute approximately the entire solid carrier in thegranular insecticide, and which oil is substantially non-volatile atatmospheric temperatures and relatively non-drying, the said granularinsecticide being relatively free of loose, unattached pulverulentparticles, substantially free from clumping and readily pourable and isrelatively dustless upon being poured from a container and under normalconditions of hand distribution.

3. An insecticidal composition in granular form, suitable for useagainst flies and other insects, characterized by inorganic, non-porous,water-insoluble granules with particle size range from 3 to 100 screenmesh, inclusive, as a carrier coated with a solution of 0,0-dimethyldithiophosphate of diethyl mercaptosuccinate in an oil, and sugar insmall particle size, which inorganic granules constitute approximatelythe entire solid carrier in the granular insecticide, and which oil issubstantially nonvolatile at atmospheric temperatures and relativelynondrying, the said granular insecticide being relatively free of loose,unattached pulverulent particles, substantially free from clumping andreadily pourable and is relatively dustless upon being poured from acontainer and under normal conditions of hand distribution.

4. An insecticidal composition in granular form characterized bygranules of particle size ranging from 3 to 100 screen mesh, inclusive,of oyster shell as a carrier coated with a mixture of an oil solution ofan organic. toxicant for the insect, and an organic attractant for theinsect, which granular oyster shell constitutes approximately the entiresolid carrier in the granular insecticide, and which oil issubstantially non-volatile at atmospheric temperatures and relativelynon-drying, the said granular insecticide being relatively free ofloose, unattached pulverulent particles, substantially free fromclumping and readily pourable and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

5. An insecticidal composition in granular form characterized bygranules of particle size ranging from'3 to 100 screen mesh, inclusive,of oyster shell as a carrier coated With a mixture of an oil solution ofan organic toxicant for the insect, an organic attractant for theinsect, and a dispersant for the toxicant-oil solution as to moisturethat comes in contact with the granules, which granular oyster shellconstitutes approximately the entire solid carrier in the granularinsecticide, and which oil is substantially nonvolatile at atmospherictemperatures and relatively non-drying, the granular insecticide beingrelatively free of loose, unattached pulverulent particles substantiallyfree from clumping and readily pourable and is relatively dustless uponbeing poured from a container and under normal conditions of handdistribution.

6. An insecticidal composition in granular form, characterized bygranules of particle size ranging from 3 to 100 screen mesh, inclusive,of granite as a carrier coated with a mixture of an oil solution of anorganic toxicant for the insect and an organic attractant for theinsect, which granite constitutes approximately the entire solid carrierin the granular insecticide, and which oil is substantially non-volatileat atmospheric temperatures and relatively non-drying, the said granularinsecticide being relatively free of loose, unattached pulverulentparticles, substantially free from clumping and readily pourable and isrelatively dustless upon being poured from a container and under normalconditions of hand distribution.

7. An insecticidal composition in granular form, characterized bygranules of particle size ranging from 3 to 100 screen mesh, inclusive,of granite as a carrier coated with a mixture of an oil solution of anorganic toxicant for the insect, an organic attractant for the insect,and a dispersant for the toxicant-oil solution as to moisture that comesin contact with the granules, which granite constitutes approximatelythe entire solid carrier in the granular insecticide, and which oil issubstantially nonvolatile at atmospheric temperatures and relativelynondrying, the said granular insecticide being relatively free of loose,unattached pulverulent particles, substantially free from clumping andreadily pourable and is relatively dustless upon being poured from acontainer and under normal conditions of hand distribution.

8. An insecticidal composition in granular form, suitable for useagainst flies and other insects, characterized by granules of particlesize ranging from 3 to 100 screen mesh, inclusive, of granite as acarrier coated with a solution of 0,0-dimethyl dithiophosphate ofdiethyl mercaptosuccinate in an oil and sugar in small particle size,which granite granules constitute approximately the entire solid carrierin the granular insecticide, and which oil is substantially non-volatileat atmospheric temperatures and relatively non-drying, the granularinsecticide being relatively free of pulverulent particles,substantially free from clumping and readily pourable, and whichgranular insecticide is relatively dustless upon pouring from acontainer and under normal conditions of hand distribution.

9. An insecticidal composition in granular form characterized bygranules of particle size ranging from 3 to 100 screen mesh, inclusive,of silica as a carrier coated with a mixture of an oil solution of anorganic toxicant for the insect, and an organic attractant for theinsect, which granular silica constitutes approximately the entire Hillsolid carrier in the granular insecticide, and which oil issubstantially non-volatile at atmospheric temperatures and relativelynon-drying, the said granular insecticide being relatively free ofloose, unattached pulverulent particles, substantially free fromclumping and readily pourable and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

10. An insecticidal composition in granular form, characterized bygranules of particle size ranging from 3 to screen mesh, inclusive, ofsilica as a carrier coated with a mixture of an oil solution of anorganic toxicant for the insect, an organic attractant for the insect,and a dispersant for the toxicant-oil solution as to moisture that comesin contact with the granules, which silica constitutes approximately theentire solid carrier in the granular insecticide, and which oil issubstantially non-volatile at atmospheric temperatures and relativelynon-drying, the said granular insecticide being relatively free ofloose, unattached pulverulent particles, substantially free fromclumping and readily pourable and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

11. An insecticidal composition in granular form, characterized bygranules of oyster shell of particle size ranging from 3 to 100 screenmesh, inclusive, as a carrier and forming approximately the entire solidcarrier, the major portion by weight of the particles of shell rangingwithin 10 to 20 screen mesh, and which granules of oyster shell arecoated with a mixture of an oil solution of an organic toxicant for theinsects and an organic attractant for the insects, which oil issubstantially non-volatile at atmospheric temperatures and relativelynon-drying, the said granular insecticide being relatively free ofloose, unattached pulverulent particles, substantially free fromclumping and readily pourable and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

12. An insecticidal composition in granular form, char acterized bygranules of oyster shell of particle size ranging from 3 to 100 screenmesh, inclusive, as a carrier and forming approximately the entire solidcarrier, the major portion by weight of the particles of shell rangingwithin 10 to 20 screen mesh, and which granules of oyster shell arecoated with a mixture of an oil solution of anorganic toxicant for theinsects, an organic attractant for the insects, and a dispersant for thetoxicant-oil solution as to moisture that comes in contact with thegranules, which oil is substantially non-volatile at atmospherictemperatures and relatively non-drying, the said granular insecticidebeing relatively free of loose, unattached pulverulent particles,substantially free from clumping and readily pourable and is relativelydustless upon being poured from a container and under normal conditionsof hand distribution.

13. An insecticidal composition in granular form suitable for useagainst flies and other insects, characterized by granules of particlessize ranging from 3 to 100 screen mesh, inclusive, of calcareous shellas a carrier coated with a mixture of a solution of 0,0-dimethyldithiophosphate of diethyl mercaptosuccinate in an oil, and sugar insmall particle size, which granular calcareous shell constitutes notless than substantially twothirds by weight of the entire carrier, andcomprises the major component by weight in the granular insecticide, andwhich oil is substantially non-volatile at atmospheric temperatures andrelatively non-drying, the said granular insecticide being relativelyfree of loose, unattached pulverulent particles, substantially free fromclumping and readily pourable and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

14. An insecticidal composition in granular form suitable for useagainst flies and other insects, characterizccl by granules of particlesize ranging from 3 to 100 l r i screen mesh, inclusive, of calcareousshell as a carrier coated with a mixture of a solution of 0,0-dimethyldithiophosphate of diethyl mercaptosuccinate in an oil, sugar in smallparticle size, and a dispersant for the toxicant-oil solution as tomoisture that comes in contact with the granules, which granularcalcareous shell constitutes not less than substantially two-thirds byweight of the entire carrier, and comprises the major component byweight in the granular insecticide, and which oil is substantiallynon-volatile at atmospheric temperatures and. relatively non-drying, thesaid granular insecticide being relatively free of loose, unattachedpulverulent particles, substantially free from clumping and readilypourable and is relatively dustless upon being poured from a containerand under normal conditions of hand distribution.

15. An insecticidal composition in granular form, characterized byinorganic, non-porous, water-insoluble granules with particle size rangefrom 3 to 100 screen mesh, inclusive, as a carrier coated with aconcentrated aqueous solution of sorbitol containing at least /3sorbitol by Weight with the organic toxicant for the insect and anorganic attractant for the insect, said sorbitol being in the proportionof approximately O.5%-3% by weight of the total granular insecticide,which inorganic granules constitute not less than substantiallytwo-thirds by Weight in the granular insecticide, the said solution ofsorbitol being employed in such quantity that the said granularinsecticide is relatively free of loose, unattached pulverulentparticles, substantially free from clumping and readily pourable, and isrelatively dustless upon being poured from a container and under normalconditions of hand distribution.

16. An insecticidal composition in granular form, characterized bycalcareous shell granules with particle size range from 3 to 100 screenmesh, inclusive, as a carrier coated with a concentrated aqueoussolution of sorbitol containing at least /3 sorbitol by weight with anorganic toxicant for the insect and an organic attractant for theinsect, said sorbitol being in the proportion of approximately 0.5 %3%by weight of the total granular insecticide, which shell granulesconstitute not less than substantially two-thirds by weight in thegranular insecticide, the said solution of sorbitol being employed insuch quantity that the said granular insecticide is relatively free ofloose, unattached pulverulent particles, substantially free fromclumping and readily pourable, and is relatively dustless upon beingpoured from a container and under normal conditions of handdistribution.

17. The composition set out in claim 15 wherein the 18 solution ofsorbitol contains a thickening agent which is normally solid to conferbody thereto.

18. The composition set out in claim 16 wherein the solution of sorbitolcontains a thickening agent which is normally solid to confer bodythereto.

19. An insecticidal composition in granular form, characterized byinorganic, non-porous, water-insoluble granules with particle size rangefrom 3 to screen mesh, inclusive, as a carrier coated with a solution ofan organic toxicant in a vehicle which is a member of the groupconsisting of a non-volatile, relatively nondrying oil and aconcentrated aqueous solution of sorbi tol containing at least /3sorbitol by Weight, said sorbitol being in the proportion ofapproximately 0.5%-3% by Weight of the total granular insecticide, andan organic attractant for the insect, which inorganic granulesconstitute not less than substantially two-thirds by weight in thegranular insecticide, the respective coating liquids being employed insuch quantity that the said granular insecticide is relatively free ofloose, unattached pulverulent particles, substantially free fromclumping and readily pourable, and is relatively dustless upon beingpoured from a container.

20. An insecticidal composition in granular form, characterized bygranules of particle size ranging from 3 to 100 screen mesh, inclusive,of calcareous shell, as a carrier coated with a solution of an organictoxicant in a vehicle which is a member of the group consisting of anon-volatile, relatively non-drying oil and a concentrated aqueoussolution of sorbitol containing at least /3 sorbitol by weight with anorganic toxicant for the insect, said sorbitol being in the proportionof approximately 0.5-3% by weight of the weight of the total granularinsecticide and an organic attractant for the insect, which calcareousshell granules constitute not less than substantially two-thirds byWeight in the granular insecticide, the respective coating liquids beingemployed in such quantity that the said granular insecticide isrelatively free of loose, unattached pulverulent particles,substantially free from clumping and readily pourable, and is relativelydustless upon being poured from a container and under normal conditionsof hand distribution.

References Cited in the file of this patent UNITED STATES PATENTS1,450,128 Baker Mar. 27, 1923 2,263,827 Siegler Nov. 25, 1941 FOREIGNPATENTS 708,155 Great Britain Apr. 28, 1954

1. AN INSECTICIDAL COMPOSITION IN GRANULAR FORM, CHARACTERIZED BYINORGANIC, NON-POROUS, WATER-INSOLUBLE GRANULES WITH PARTICLE SIZE RANGEFROM 3 TO 10 SCREEN MESH, INCLUSIVE, AS A CARRIER COATED WITH AN OILSOLUTION OF AN ORGANIC TOXICANT FOR THE INSECT, AND AN ORGANICATTRACTANT FOR THE INSECT, WHICH INORGANIC GRANULES CONSTITUTEAPPROXIMATELY THE ENTIRE SOLID CARRIER IN THE GRANULAR INSECTICIDE, ANDWHICH OIL IS SUBSTANTIALLY NON-VOLATILE AT ATMOSPHERIC TEMPERATURES ANDRELATIVELY NON-DRYING, THE SAID GRANULAR INSECTICIDE BEING RELATIVELYFREE OF LOOSE, UNATTACHED PULVERULENT PARTICLES, SUBSTANTIALLY FREE FROMCLUMPING SAID READILY PURABLE, AND IS RELATIVELY DUSTLESS UPON BEINGPOURED FROM A CONTAINER AND UNDER NORMAL CONDITIONS OF HANDDISTRIBUTION.